Traumatic injury is the leading cause of death for individuals between the ages of 5 and 44, and blood loss is the major factor in both civilian and battlefield traumas. Following injury, hemostasis is established through a series of coagulatory events including platelet activation. However, with severe injuries, these processes are insufficient and result in uncontrolled bleeding. Methods to staunch bleeding have included pressure dressings and absorbent materials, but these treatments are limited to compressible and exposed wounds. Alternatives have included allogeneic platelet transfusions, clotting factors, and platelet substitutes, but efficacy, immunogenicity, and thrombosis have stalled their application. Immediate intervention is one of the most effective means of minimizing mortality associated with severe trauma.
Administration of allogenic platelets are a logical means to halt bleeding; however, platelets have a short shelf life, and administration of allogenic platelets can cause graft versus host disease, alloimmunization, and transfusion-associated lung injuries. Recombinant factors including Factor VIIa can augment hemostasis, but immunogenic and thromboembolic complications are unavoidable risks. Nonetheless, administration of recombinant factors has become the standard of care in a number of trauma and surgical situations where bleeding cannot otherwise be controlled. Non-platelet alternatives including red blood cells modified with the Arg-Gly-Asp (RGD) sequence, fibrinogen-coated microcapsules based on albumin, and liposomal systems have been studied as coagulants, but toxicity, thrombosis, and limited efficacy have stalled many of these products.